Aldwinckle then joined a small Japanese trading company in Sapporo. It was this experience, he recounts, that started him down the path of the controversial activist that he would later become. "This was a watershed in my life," Arudou writes. "… and it polarized my views about how I should live it. Although working [in Japan] made my Japanese really good — answering phones and talking to nasty, racist, and bloody-minded construction workers from nine to six — there was hell to pay every single day." Arudou contends that he was the object of racial harassment. Aldwinckle quit the company. In 1993 he joined the faculty of Business Administration and Information Science at the Hokkaido Information University, a private university in Ebetsu, Hokkaidō, teaching courses in English as a foreign language. As of 2007, he is an associate professor.

Japanese naturalization

Aldwinckle became a permanent resident of Japan in 1996. He obtained Japanese citizenship in 2000, whereupon he changed his name to , whose kanji he says have the figurative meaning of "a person who has a road and is going out on it." To allow his wife and children to retain their Japanese family name, he adopted the legal name — a combination of his wife’s Japanese name and his new transliterated full name. As reasons for naturalization, he cited the right to vote, other rights, and increased ability to stand on his rights; he renounced his U.S. citizenship in 2002 as required by Japanese law.

Family and divorce

Ayako Sugawara gave birth to two daughters. Arudou described one of his children as "viewed as Japanese because of her looks" and the other as "relegated to gaijin status, same as I" because of physical appearances. According to Arudou's writings, when he took his family to the Yunohana Onsen to test the rules of the onsen, the establishment stated that they would allow one girl to enter the onsen and but would have to refuse the other on the basis of their appearances.

Arudou and his wife divorced in September 2006. Following their divorce, Arudou petitioned the Sapporo Family Court to have his ex-wife’s family name, "Sugawara" removed from his koseki. The court granted the request and his name was officially changed to Arudou Debito in November 2006.

Activism

Otaru onsen lawsuit

Arudou was one of three plaintiffs in a racial discrimination lawsuit against the Yunohana Onsen in Otaru, Hokkaidō. Yunohana maintained a policy to exclude non-Japanese patrons; the business stated that it implemented the policy after Russian sailors scared away patrons from one of its other facilities. After reading an e-mail posted to a mailing list digest complaining of Yunohana's policy in 1999, Arudou visited the hot spring (onsen), along with a small group of Japanese, White, and East Asian friends, in order to confirm that only visibly non-Japanese people were excluded.

Arudou assumed that when he returned in 2000 as a naturalized Japanese citizen, he would not be refused. The manager accepted that Arudou was a Japanese national but refused entry on the grounds that his foreign appearance could cause existing Japanese customers to assume the onsen was admitting foreigners, i.e drunk Russian sailors which were causing problems in that locality, and take their business elsewhere.

Arudou and two co-plaintiffs, Kenneth Lee Sutherland and Olaf Karthaus, in February 2001 then sued Yunohana on the grounds of racial discrimination, and the City of Otaru for violation of the United Nations Convention on the Elimination of All Forms of Racial Discrimination, a treaty which Japan ratified in 1996. On November 11, 2002, the Sapporo District Court ordered Yunohana to pay the plaintiffs 1 million JPY each (about $25,000 United States dollars in total) in damages. The court stated that "refusing all foreigners without exception is 'unrational discrimination' [that] can be said to go beyond permissible societal limits." The Sapporo High Court dismissed Arudou's claim against the city of Otaru for failing to create an anti-discrimination ordinance; the court ruled that the claim did not have merit. The Sapporo High Court upheld these rulings on September 16, 2004 and the Supreme Court of Japan denied review on April 7, 2005.

Other protests

In 2003, Arudou dressed up as a seal and joined a group protesting the decision by Nishi Ward, Yokohama to grant Tama-chan the seal an honorary jūminhyō (residency registration), which is not available to foreign residents.

In June 2008, Arudou lodged a complaint with the Hokkaidō Prefectural Police, claiming that its officers were targeting foreigners as part of a security sweep prior to the 34th G8 summit in Tōyako, Hokkaidō. This followed an incident in which Arudou refused to show identification when requested by a police officer at New Chitose Airport. After meeting with police representatives at their headquarters, Arudou held a press conference, which he described as the "third-best press conference I’ve ever done". The press conference was covered by a local television station.

Methods

Arudou maintains an active online profile In her review of Japanese Only (see "Publications" below), Yuki Honjo praised Arudou's "comprehensive website with thousands of pages of material" as an "excellent resource". Nevertheless, Honjo noted that "Arudou's brand of 'Internet activism'... seems almost quaint" and his lack of engagement with more contemporary protest methods, such as flash mobs, blogs or wikis, essentially means "he remains the old-fashioned pamphleteer." Arudou has since set up a blog where he comments on an almost daily basis.

Alex Kerr, author of the book Dogs and Demons has criticised Arudou for his "openly combative attitude", an approach that Kerr thinks usually "fails" in Japan and may reinforce the conservative belief "that gaijin are difficult to deal with". Nevertheless, he comments that "perhaps we who live here are slow to stick our necks out...and quick to self-censor...to get along....". He also sees Arudou's decision to naturalise as bringing "the dialogue inside Japan. His activities reveal the fact that gaijin and their gaijin ways are now a part of the fabric of Japan's new society.

Publications

Arudou has written a book about the 1999 Otaru hot springs incident. Arudou originally wrote the book in Japanese; the English version, (ISBN 4-7503-2005-6), was published in 2004 and revised in 2006. The book is listed in the Japan Policy Research Institute's recommended library on Japan. Jeff Kingston (Temple University Japan), in a review for The Japan Times, described the book as an "excellent account of his struggle against prejudice and racial discrimination. Yuki Allyson Honjo criticized "Japanese Only" on Japanreview.net. Noting her sympathy for his plight and that her co-editor Peter Scalise had vetted a draft copy, she concluded "This book does not do the thought-provoking and complex topic of racial integration and cultural tolerance justice...."

Arudou's second book was coauthored with and titled . This was a bilingual book, which provided information on visas, starting businesses, securing jobs, resolving legal problems, and planning for the future from entry into Japan to death. Donald Richie of The Japan Times said that out of the guides for new residents in Japan, Handbook was the fullest and consequently the best.

Arudou has also written pieces for the on-line academic website Japan Focus and had his work published by the Japan Policy Research Institute, which later placed his article online when it moved to a web format.

Arudou writes a guest column, "Just Be Cause", for The Japan Times. In August 2008, Arudou drew an analogy between the words "gaijin" and "nigger", arguing that the status of "gaijin" as politically incorrect was well deserved. This prompted a large reader response, with most of the published responses finding the analogy inappropriate. This process was repeated roughly one month later, when Arudou wrote another article standing by his original statement. Again, most published responses were critical of the analogy.